Rice University and Penn State University researchers have collaborated to create a sponge capable of soaking up oil spilled in water, which could have a profound impact on the environment.

Daniel Hashim, study leader and graduate student at Rice University, along with Pulickel Ajayan, professor in Mechanical Engineering and Materials Science at Rice University, and Mauricio Terrones, professor of physics, materials science and engineering at Penn State University, are all responsible for the latest creation.

According to the research team, the sponges are made of nanotubes that had a bit of the chemical element boron added to the carbon. By adding boron to the carbon, the nanotubes turned into solid, yet spongy blocks.

Boron is the main secret ingredient behind the nanosponges. By adding boron, the nanotubes grew bends and "elbows" to help produce covalent bonds, which allow the nanosponges to perform the way they do. The sponges are 99 percent air, can be manipulated using magnets, and conduct electricity. They're also superhydrophobic, meaning they float better because they dislike water, and oleophilic, meaning they're attracted to oil.

These nanosponges are capable of soaking up oil and being reused after doing so. According to the team, the nanosponges can undergo about 10,000 compressions where oil is soaked into the sponge, burned off, and returned to the water to soak more. Also, the sponges can hold more than a hundred times their weight in oil.

Nanosponge with boron [Source: Rice University]

"Our goal was to find a way to make three-dimensional networks of these carbon nanotubes that would form a macroscale fabric — a spongy block of nanotubes that would be big and thick enough to be used to clean up oil spills and to perform other tasks,” said Terrones. “We realized that the trick was adding boron — a chemical element next to carbon on the periodic table — because boron helps to trigger the interconnections of the material. To add the boron, we used very high temperatures and we then ‘knitted’ the substance into the nanotube fabric.

"Oil-spill remediation and environmental cleanup are just the beginning of how useful these new nanotube materials could be. For example, we could use these materials to make more efficient and lighter batteries. We could use them as scaffolds for bone-tissue regeneration. We even could impregnate the nanotube sponge with polymers to fabricate robust and light composites for the automobile and plane industries.”

Such nanosponges could come in handy one day for major spills, such as the BP oil spill that occurred in April 2010 when the Deepwater Horizon drilling rig exploded and leaked oil into the Gulf of Mexico for three months. It was described as the "worst spill in U.S. history."

This also isn't the first nanosponge to be used for absorbing oil. In early 2010, Dr. Paul Edmiston of the College of Wooster in Ohio created a glass nanosponge capable of removing oil from water.